1. Field of the Invention
The present invention relates generally to a tooling assembly for reforming an end shell, and in particular, is concerned with a tooling assembly which reforms an end shell to provide a reinforcing channel around a central wall portion of an end shell.
2. Description of the Related Art
It is well known that a conventional can end may have its pressure resistance increased by increasing the depth of an annular groove with respect to the end's central panel and maintaining a tight radius of curvature in the annular groove.
In particular, U.S. Pat. No. 4,109,599 discloses a method of forming a pressure resistant end shell. An upper tool includes an inside supporting surface which engages against a frustoconical wall portion of the end shell. The central wall portion of the end shell is supported by a lower tool. As the upper and lower tools are moved toward each other, an annular groove is formed around the central wall portion. The upper tool does not engage the central wall portion. Thus, the reforming is performed without support on both sides of the central wall portion. Without such support, the radius of the annular groove may vary. If the radius of the annular groove is not maintained, the performance of the end shell is jeopardized. Furthermore, without such support, the angularity of the frustoconical wall portion may vary and become unacceptable.
Consequently, a need exists for improvements in tooling for reforming an end shell. It is desirable that such improvements provide a reliable assembly for forming a pressure-resistance end shell while maintaining critical parameters such as central wall radius and frustoconical wall angularity.